THE BEAR FACTS – March 2007

By Barbara Mellon

When that burly black bear ambles across your yard, or breaks into your trashcans, what are you thinking? Do you see this beast as a pest? A threat? An awesome visitor? I’ve recently discovered there is a whole other way of looking at these wondrous creatures.

Study of the hibernation process of bears has shown these animals to be medical marvels. For up to 100 days, a hibernating bear, curled up in a cave, hollowed out tree, or rock crevice, will go without food, drink, activity, or the expulsion of bodily waste. And yet, come spring it is a healthy animal that emerges from its den.

In preparation for their winter nap, bears will spend the latter part of the summer and the fall gorging on foods high in carbohydrates. Forget the 10 extra pounds so many of us put on during the holidays, or the famous “freshman fifteen” that expands the waistlines of first-year college students. A black bear can gain up to 30 pounds per week while priming itself for hibernation. Along with this tremendous weight gain comes increased cholesterol levels, twice as high as normal summer levels.

Under similar conditions, my doctor would probably prescribe all kinds of medicines and treatments, or even have me rushed to the hospital. But despite the increased cholesterol levels, bears are not subject to hardening of the arteries or cholesterol-induced gallstones the way we humans are.

Researchers have studied this phenomenon, and discovered that hibernating bears produce a bile juice called ursodeoxycholic acid. They find that giving this substance to humans suffering from gallstones can dissolve the stones and eliminate the need for surgery.

In a human, the inability to urinate for an extended period of time is cause for medical concern. The body of a hibernating bear, though, is not poisoned by the buildup of waste products such as urea. In fact, the urea is broken down, and the resulting nitrogen is used to build protein. This protein is important in maintaining the bear’s muscle and organ tissue. During the hibernation period, it is only the bear’s fat tissue that is used for energy. When the fat is burned, carbon dioxide and water are left, with no other residues. This fat yields twice the energy as protein or carbohydrates would. The production of such a great amount of energy ensures that the bear’s body temperature will drop no more than 12° during the hibernation period.

The study of how the body of a bear works during hibernation could lead to all kinds of applications. New treatments for kidney disease, osteoporosis, cardiovascular disease, obesity, diabetes, and gall bladder problems could be developed, in many cases eliminating or reducing the need for surgery or dialysis. The ability to put a person into hibernation could prove helpful when treating severely burned or injured patients. And the space program could benefit by understanding how the hibernating animal maintains muscle strength and bone mass, both problems for those living in the weightlessness of the space stations.

The next time you come across a black bear, I suggest you bow to him. He may have the future of your health in his paws.~